Generally, a breakwater is a structure to dissipate the waves from the open sea to the inland sea, thereby protecting the facilities at a harbor or the shores.
The conventional breakwaters were constructed merely to block the seawater currents from the open sea to the harbor side or shore for the primary purpose for protection of the waves surged to harbor, which were built in an upright structure using a caisson or a rubble mound.
However, the currents between the inside and outside seawaters of the harbor were blocked by the breakwater, which led to the serious problems of the marine pollutions caused by the deposition of garbage to the seabed and the deterioration of beaches.
In order to solve theses problems, the permeable breakwaters were proposed.
The typical examples of the permeable breakwaters in an upright type are disclosed in the Korean Utility Model Registration No. 303,600 and Korean Patent Registration No. 374,181.
The Korean Utility Model Registration No. 303,600 discloses a permeable upright breakwater having a base part with a plurality of conduits, through which a tide may flow.
However, although the tide may pass the upright breakwater, but there are problems of the complicated method of construction, the insufficient wave dissipation function and the needs of the separate tetrapods.
The Korean Patent Registration No. 374,181 discloses a tide permeable breakwater which comprises a base placed at the sea bottom, a plurality of culverts provided on the top of the base along the total length of the breakwater so that the seawater passages in a width direction may be arranged, a plurality of breakwater modules arranged on the upper surface of the culverts toward the open sea so as to form the slope, on which tetrapods are mounted, and a plurality of the hollow blocks vertically arranged on the harbor side surface of the culverts, of which the top portions are covered with a cap concrete.
However, there are problems that the construction method of the permeable upright breakwater is complicated and the permeablity of the tide is very limited.
Also, since the both conventional breakwater were constructed by using an upright structure or a bubble mound type, such structures have a common problem that a destruction of a portion of the breakwater is led to the consecutive destruction of the total breakwater.